The present invention relates generally to antimicrobials for personal care products and, more specifically, to a blend of oregano extract containing carvacrol and caprylic acid.
Consumer demand has shifted to the purchasing of personal care products with “all natural” ingredients. Manufacturers have answered the demand by changing existing formulations or by creating new ones.
For personal care formulators, no functional ingredient has been the most difficult to change than the preservative. Preservatives are necessary to maintain the stability of a formulation 1 to 2 years. Widely used preservatives are in the paraben class: methyl-, butyl-, propyl-, heptyl-, ethyl-. These compounds are highly efficacious on bacteria and fungi, but they have received negative attention in regards to being a possible cause of breast cancer. Some natural preservatives are on the market but have varying degrees of efficacy.
Studies have shown that carvacrol disrupts the membrane potential of bacteria, and recently a cultivar of oregano containing ≧5% of the molecule by dry weight of material has been developed. Oregano oil containing 94.6% carvacrol has been shown to be an effective disinfectant ingredient against bacteria, yeast, and mold when used at a 1.0% inclusion of carvacrol.
The purpose of this study was to test the efficacy of a carvacrol and caprylic acid blend first by finding screening for inhibition and then by conducting a preservative efficacy test, USP 51, in skin creams. This method requires a 1-3 log reduction after 14 days with no increase in growth after 28 days for Escherichia coli, Staphylococcus aureus, Pseudomonas, aeruginosa, Candida albicans, and Aspergillus brasiliensis. 